A reflection-type exposure mask is used in photolithography using extreme ultraviolet (EUV) light. The reflection-type exposure mask for EUV lithography typically has a multilayer film provided on a substrate so as to selectively reflect the EUV light. For EUV exposure, the reflection-type exposure mask is irradiated and the reflected light is then ultimately focused onto a photoresist film on a wafer substrate to transfer a predetermined pattern of unexposed and exposed regions to the photoresist film. To improve the fidelity of the transferred pattern to the mask pattern, improved contrast in the optical image formed in the resist film would be desirable.